zig/lib/std/buf_set.zig
Andrew Kelley cb38bd0a14
rename std.heap.direct_allocator to std.heap.page_allocator
std.heap.direct_allocator is still available for now but it is marked
deprecated.
2019-11-25 17:25:06 -05:00

80 lines
2.1 KiB
Zig

const std = @import("std.zig");
const StringHashMap = std.StringHashMap;
const mem = @import("mem.zig");
const Allocator = mem.Allocator;
const testing = std.testing;
pub const BufSet = struct {
hash_map: BufSetHashMap,
const BufSetHashMap = StringHashMap(void);
pub fn init(a: *Allocator) BufSet {
var self = BufSet{ .hash_map = BufSetHashMap.init(a) };
return self;
}
pub fn deinit(self: *const BufSet) void {
var it = self.hash_map.iterator();
while (true) {
const entry = it.next() orelse break;
self.free(entry.key);
}
self.hash_map.deinit();
}
pub fn put(self: *BufSet, key: []const u8) !void {
if (self.hash_map.get(key) == null) {
const key_copy = try self.copy(key);
errdefer self.free(key_copy);
_ = try self.hash_map.put(key_copy, {});
}
}
pub fn exists(self: BufSet, key: []const u8) bool {
return self.hash_map.get(key) != null;
}
pub fn delete(self: *BufSet, key: []const u8) void {
const entry = self.hash_map.remove(key) orelse return;
self.free(entry.key);
}
pub fn count(self: *const BufSet) usize {
return self.hash_map.count();
}
pub fn iterator(self: *const BufSet) BufSetHashMap.Iterator {
return self.hash_map.iterator();
}
pub fn allocator(self: *const BufSet) *Allocator {
return self.hash_map.allocator;
}
fn free(self: *const BufSet, value: []const u8) void {
self.hash_map.allocator.free(value);
}
fn copy(self: *const BufSet, value: []const u8) ![]const u8 {
const result = try self.hash_map.allocator.alloc(u8, value.len);
mem.copy(u8, result, value);
return result;
}
};
test "BufSet" {
var bufset = BufSet.init(std.heap.page_allocator);
defer bufset.deinit();
try bufset.put("x");
testing.expect(bufset.count() == 1);
bufset.delete("x");
testing.expect(bufset.count() == 0);
try bufset.put("x");
try bufset.put("y");
try bufset.put("z");
}